Silicon carbide thyristors are described, for example, in U.S. Pat. No. 5,539,217 (the '217 patent) the disclosure of which is incorporated herein by reference as if set forth fully. The thyristors described in the '217 patent are three terminal devices having a gate and one of an anode or a cathode on a first side of the device and the other of the anode and the cathode on the opposite side of the device. Such silicon carbide thyristors may exhibit improved power handling capabilities over similar silicon thyristors.
Light-activated thyristors having an integrated light source and a silicon carbide active layer have been described in U.S. Pat. No. 5,663,580. Such devices may include four terminal devices including anode and cathode terminals for a light emitting diode which acts to trigger a thyristor having its own anode and cathode terminals.
Light activated silicon thyristors have been utilized in high power applications. For example, optically triggered parallel lateral thyristors are described in U.S. Pat. No. 4,779,126.
While silicon carbide thyristors may provide improved power handling capabilities over comparably sized silicon devices, it may be difficult to form large scale thyristors in silicon carbide. For example, in silicon, a single thyristor may be made on a wafer such that the thyristor is substantially the same size as the wafer. However, manufacturing defect-free silicon carbide wafers may be difficult. Thus, a device which consumes an entire silicon carbide wafer may have defects incorporated into the device which may limit its performance.
Moreover, the large size of silicon thyristors makes the design of an optical driver for such devices a challenge, since it is desirable to apply a uniform light to a large surface area of the device.